Heme oxygenase 1 regulates apoptosis induced by heat stress in bovine ovarian granulosa cells via the ERK1/2 pathway.

Heat stress can inhibit follicular development in dairy cows, and thus can affect their reproductive performance. Follicular granulosa cells can synthesize estrogen, that affects the development and differentiation of follicles by apoptosis. Heme oxygenase 1 (HO-1/heat shock protein 32) plays an antiapoptotic and cytoprotective role in various cells during stress-induced apoptosis, but little is known about its definitive function in bovine (ovarian) granulosa cells (bGCs). In our study, the roles and mechanism of HO-1 on the heat stress-induced apoptosis of bGCs were studied. Our results show that the expression of HO-1 was significantly increased under heat stress. Moreover, HO-1 silencing increased apoptosis, whereas its overexpression dampened apoptosis by regulating the expression of Bax/Bcl-2 and the levels of cleaved caspase-3. In addition, HO-1 can also play a cytoprotective role by affecting estrogen levels and decomposing heme to produce biologically active metabolite carbon monoxide (CO). Meanwhile, CO significantly increased the level of HO-1, decreased Bax/Bcl-2 levels, and inhibited the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway. The apoptosis of ovarian GCs can affect the secretion of estrogen and lead to disorder of the ovarian microenvironment, thus affecting the normal function of the ovary. Our results indicate that HO-1 acts as a cytoprotective enzyme and plays a protective role in heat-induced apoptosis of bGCs. In conclusion, HO-1 and its metabolite CO inhibit the apoptosis of bGCs induced by heat stress through the ERK1/2 pathway. The results of this study provide a valuable clue for improving the fertility of heat stressed cows in summer.

SIRT7 depletion inhibits cell proliferation, migration, and increases drug sensitivity by activating p38MAPK in breast cancer cells.

SIRT7 is a member of the sirtuin family of proteins that are known to be associated with tumor development. However, the functional roles and molecular mechanisms underlying the function of SIRT7 in breast cancer cell survival and tumor development remain unclear. Recent studies demonstrated that SIRT7 is upregulated in breast cancer cells and tissues. In the present study, we systematically explored the roles of SIRT7 in the growth of breast cancer cells and tumors both in vitro and in vivo. Our results showed that SIRT7 plays a major role in facilitating cell survival by promoting cell proliferation and inhibiting apoptosis. SIRT7 depletion significantly inhibited cell invasion and wound healing by blocking cell cycle progression and inducing cell apoptosis. Meanwhile, SIRT7 depletion can increase the sensitivity of breast cancer cells to doxorubicin (DOX). Xenograft model studies showed that stable silencing of SIRT7 inhibited tumor growth and enhanced tumor sensitivity to DOX. Further research revealed that p38MAPK is involved in SIRT7-mediated regulation of breast cancer cell proliferation and tumor growth. Taken together, our results showed that SIRT7 plays a critical role in breast cancer cell survival, migration, and tumor growth, and increased the efficiency of DOX treatment both in vitro and in vivo. Therefore, SIRT7 is a promising therapeutic target in breast cancer treatment.

Heat shock protein 32/heme oxygenase-1 protects mouse Sertoli cells from hyperthermia-induced apoptosis by CO activation of sGC signalling pathways.

Heat shock protein 32 (Hsp32)/heme oxygenase-1 (HO-1) may be a key enzyme for the protection of cells against stress. Its anti-apoptotic effect has been attributed to its product, carbon monoxide (CO), in many types of cells. However, whether its anti-apoptotic mechanism plays a role in Sertoli cells (SCs) is not yet clear. We hypothesise that Hsp32/HO-1 and CO generated from it provide survival advantages in SCs by preventing apoptosis under heat exposure. After treatment of cultured SCs with hyperthermia and/or Hsp32/HO-1 activater hemin, apoptosis was measured valuated by annexin V-FITC and caspase-3 activation. We have also analysed the Hsp32/HO-1-derived CO content of cultured media and cyclic guanosine monophosphate (cGMP) production by enzyme-linked immunosorbent assay (ELISA). Hyperthermia induced SCs apoptosis, while preincubation with hemin suppressed SC hyperthermia-induced apoptosis. Hyperthermia and/or hemin increase Hsp32/HO-1 gene expression and the production of CO, which, in turn, stimulates the generation of cGMP. The results suggest that Hsp32/HO-1 is a protective factor in heat-stressed SCs, and that CO generated from Hsp32/HO-1 is involved in the anti-apoptotic pathway.

(4-Meth-oxy-phen-yl)(4-propyl-cyclo-hex-yl)methanone.

The asymmetric unit of the title compound, C17H24O2, contains two independent mol-ecules with different conformations. The least-squares plane through the cyclohexane ring makes dihedral angles of 52.9 (5) and 81.4 (4)° with the benzene ring in the two molecules. The cyclo-hexane ring adopts a chair conformation in both mol-ecules. In the crystal, weak C-H⋯O hydrogen bonds link mol-ecules related by translation in [100] into two crystallographically independent chains.

[Effect of spinal glutamate transporter 1 on chronic constriction injury of sciatic nerve and morphine tolerance of rats].

In order to investigate the role of spinal glutamate transporter 1 (GLT-1) in the neuropathic pain and morphine tolerance, rat chronic constriction injury (CCI) of sciatic nerve was performed, and the mechanical allodynia was evaluated by mechanical withdrawal threshold (MWT), the expression of GLT-1 was measured by real-time PCR and Western blotting analysis. The results showed that compared to sham group, the MWT of CCI group had decreased approximately 80%. Administration of morphine alone could develop tolerance rapidly in initial two days, and then had no significant difference with CCI group, the expression of GLT-1 was down-regulated. Ceftriaxone sodium alone could improve mechanical allodynia. Co-administration of ceftriaxone sodium with morphine attenuated morphine tolerance and up-regulated GLT-1 expression, and the MWT remained at high level after 6 days. In conclusion, change of spinal GLT-1 expression and function has close correlation with the development of neuropathic pain and morphine tolerance.

SIRT7 Regulates Lipopolysaccharide-Induced Inflammatory Injury by Suppressing the NF-κB Signaling Pathway.

Mastitis has severely affected the cattle industry worldwide and has resulted in decreased dairy production and cattle reproduction. Although prevention and treatment methods have been implemented for decades, cattle mastitis is still an intractable disease. Sirtuin 7 (SIRT7) is an NAD+-dependent deacetylase that is involved in various biological processes, including ribosomal RNA synthesis and protein synthesis, DNA damage response, metabolism, and tumorigenesis. However, whether SIRT7 participates in inflammation remains unknown. Our results revealed that SIRT7 is downregulated in tissue samples from mastitic cattle. Therefore, we isolated dairy cow mammary epithelial cells (DCMECs) from breast tissues and developed an in vitro model of lipopolysaccharide- (LPS-) induced inflammation to examine SIRT7 function and its potential role in inflammation. We showed that SIRT7 was significantly downregulated in LPS-treated DCMECs. SIRT7 knockdown significantly increased the LPS-stimulated production of inflammatory mediators, like reactive oxygen and nitric oxide, and upregulated TAB1 and TLR4. In addition, SIRT7 knockdown significantly increased the phosphorylation of TAK1 and NF-κBp65 in LPS-treated DCMECs. Moreover, SIRT7 knockdown promoted the translocation of NF-κBp-p65 to the cell nucleus and then increased the secretion of inflammatory cytokines (IL-1ß and IL-6). In contrast, SIRT7 overexpression had the opposite effects when compared to SIRT7 knockdown in LPS-treated DCMECs. In addition, SIRT7 overexpression attenuated LPS-induced DCMEC apoptosis. Taken together, our results indicate that SIRT7 can suppress LPS-induced inflammation and apoptosis via the NF-κB signaling pathway. Therefore, SIRT7 may be considered as a potential pharmacological target for clinical mastitis therapy.

Long noncoding RNA and mRNA profiling in MDA-MB-231 cells following RNAi-mediated knockdown of SIRT7.

Breast cancer is one of the most common malignant cancers among women and a major clinical obstacle. Although studies have reported the abnormal expression of SIRT7 in breast cancer, whether the function of SIRT7 regulates the expression of long noncoding RNAs (lncRNAs) in breast cancer remains unknown. We aimed to determine the differential expressions of mRNAs and lncRNAs associated with SIRT7 and understand the regulatory mechanism of SIRT7 in breast cancer. RNA sequencing was performed to explore the transcriptome in MDA-MB-231 cells after SIRT7 depletion, and a total of 50,634 different transcripts were identified. In comparison with the negative control, siSIRT7 groups showed 240 differentially expressed mRNAs and 26 differentially expressed lncRNAs. Gene ontology analysis revealed that the differentially expressed mRNAs mainly regulated DNA replication, CXCR chemokine receptor binding, and maturation of large subunit rRNA from tricistronic rRNA transcript, nucleoplasm, mitochondrion, and NAD+ ADP-ribosyltransferase activity. Kyoto Encyclopedia of Genes and Genomes analysis showed that the differentially expressed mRNAs were mainly involved in pathways associated with MAPK signaling pathway, tumor necrosis factor signaling pathway, hepatitis B, and cancer. Moreover, the target genes of the differentially expressed lncRNAs mainly regulated the carboxylic acid metabolic processes and were involved in glycolysis pathway. The mRNA-lncRNA coexpression network comprised 186 mRNAs and 23 lncRNAs. Our results provide essential data regarding differentially expressed lncRNAs and mRNAs after the depletion of SIRT7 in breast cancer cells, which may be useful to elucidate the role of SIRT7 in breast cancer development.

Changes in expression and production of heme oxygenase-1 in rats with acute liver injury induced by lipopolysaccharide.

To investigate the changes of heme oxygenase-1 (HO-1) expression and production in rats with acute liver injury induced by lipopolysaccharide (LPS), and explore the role of HO-1 in the pathogenesis of liver injury. Liver injury was assessed histologically and the serum level of alanine transaminase (ALT) and aspartate transaminase (AST) were examined. The activity of super oxide dismutase (SOD) and the content of malondialdehyde (MDA) and carbon monoxide (CO) in liver tissues were also examined at the same time. HO-1 mRNA expression was examined at different time points following LPS treatment and the expression of HO-1 protein was determined by immunohistochemical staining. Administration of LPS caused severe hepatic damage, characterized by significant elevation of serum ALT and AST levels and hepatic MDA content as well as a remarkable reduction of liver SOD activity at 24 hr as compared with those in the control group. HO-1 activity was elevated significantly after modeling, showing a time-dependent manner from 6 to 24 hr, while expression of HO-1 protein was increased remarkably from 6 to 24 hr. Endogenous CO concentration in the liver of control rats remained very low but was elevated significantly after LPS treatment (6, 12, 24 hr), which was in accordance with the changes of HO-1. HO-1 activity and protein are increased significantly in rats with acute liver injury induced by LPS, suggesting that HO-1 plays an important role in the pathogenesis of acute hepatic damage.

Upregulation of heat shock protein 32 with hemin alleviates acute heat-induced hepatic injury in mice.

Heat shock protein 32 (HSP32) is a stress response protein that can be induced by heat stress in the liver, and its induction can act as an important cellular defence mechanism against heat-induced liver injury. To investigate the functional role of HSP32 in protecting liver tissue against heat stress in mice and the mechanism by which it achieves this protective effect, HSP32 expression and carbon monoxide (CO) contents in a model of mice subjected to acute, transient heat exposure were examined. Furthermore, functional and histological parameters of liver damage and the possible involvement of oxidative stress to induce oxidative deterioration of liver functions and caspase-3 expression were also investigated in this study. We found that heat treatment of mice produced severe hepatic injury, whereas upregulation of HSP32 with hemin pretreatment prevented mice from liver damage. In contrast, addition of Sn-protoporphyrin (SnPP) to inhibit HSP32 expression completely reversed its hepatoprotective effect. It is concluded that upregulation of HSP32 by hemin could alleviate acute heat-induced hepatocellular damage in mice, and its by-product CO seems to play a more important role in hepatoprotective mechanism.

Upregulation of heat shock protein 32 in Sertoli cells alleviates the impairments caused by heat shock-induced apoptosis in mouse testis.

Heat stress results in apoptosis in testicular germ cells. A small heat shock protein (hsp), hsp32, is induced by heat stress in the testis, but little is known about its definitive function in physiological processes. To clarify the underlying role of hsp32, hsp32 expression and related signals in the heat shock pathway were analysed in mouse testes and Sertoli cells after heat stress in vivo and in vitro; meanwhile, expression of hsp32 was silenced only in the Sertoli cells using three different small interfering RNAs (siRNAs) to further verify the functional role of hsp32 in Sertoli cells, and hsp32-derived carbon monoxide (CO) contents in cultured media were analysed to clarify whether hsp32-derived CO involve in the apoptosis regulation mechanisms. The results from the in vivo experiment showed that the high expression levels of hsp32 (P < 0.05) were observed whether chronic, moderate or acute, transient heat exposure. The in vitro experiment showed that acute, transient heat exposure resulted in increases in Sertoli cells apoptosis (P < 0.01), the expression of hsp32 and caspase-3 activity; hsp32-siRNA knockdown of hsp32 expression resulted in upregulated apoptosis (P < 0.01) and caspase-3 activity (P < 0.01) in the Sertoli cells and hyperthermia increases CO (P < 0.01) release by Sertoli cells. The results suggested that upregulating hsp32 in Sertoli cells inhibits caspase-3 activity and alleviates heat-induced impairments in mouse testis; hsp32-derived CO may involve in the regulation mechanism.